Scottish salmon farming in the spotlight

WildFish explore the UK and international news articles which expose the plight of wild Atlantic salmon and the industry wide environmental, sustainability and welfare issues associated with the intensive farming of Atlantic salmon in Scotland.

Declining wild Atlantic salmon stocks

The wild Atlantic salmon is one of the UK’s most iconic species. Beginning its life in our rivers and streams, the Atlantic salmon then undergoes an incredible physiological transformation, enabling it to make its way out to sea and across thousands of miles of open water. The few that survive this epic journey, return to spawn in the same rivers and streams they were born in. Alarmingly, in the last 20 years, wild Atlantic salmon populations have declined by 70% in the UK.

Read more about this alarming decline

Scottish open-net salmon farming pollution

Far removed from this incredible migration, is the life and journey of a farmed Atlantic salmon. Selectively bred Atlantic salmon spend the first year of their lives reared in tanks in land-based freshwater hatcheries, before being transferred to netted cages in coastal waters. In these cages, hereafter referred to as ‘open net salmon farms’, due to the free flow of water though the nets that enclose the fish, the salmon will spend up to two years before being harvested.

Waste from these open net farms directly discharges into the surrounding waters causing a number of serious ecological issues.

Read more about the magnitude of this fish farm waste, and the impact this, and the chemicals used, are having on water quality and marine ecosystems.

From 2013, the environmental cost of the Scottish salmon farming industry was estimated to be £1.4billion. More about the true global cost of salmon farming

Disease, lice and high death tolls

Through the use of open nets, salmon raised in intensive farms across the west Highlands and Islands of Scotland are in constant contact with the surrounding marine environment. This method of aquaculture gives rise to a number of issues including exposure to diseases, harmful water conditions and parasites (including sea lice). The latter can build up in huge numbers on salmon farms, spreading, harming and, in some cases, killing wild salmon and sea trout.

A report by the Herald found that the Scottish salmon farming industry hit a record number of fish deaths in 2021 with nearly 30,000 tonnes of fish dying or being destroyed before harvest. Read more about this horrifying trend

The Ferret went on to report that the cost of high death rates, which average at 1 in 4 fish dying before harvest, pollution, parasites and poor animal welfare has totalled £3.3billion in Scotland since 2013, with a proportion of this loss being passed on to society.

Time to clean up their act – “Cleaner fish”

In an attempt to manage lice infestations and reduce the cost of chemical and physical lice treatments, the Scottish salmon farming industry increasingly relies on the use of “Cleaner fish”. In Scotland, species of wrasse and lumpfish, are stocked into the salmon cages, and encouraged to feed on the parasitic lice, plaguing the salmon. Despite efforts to farm these fish, this still requires a large number of wrasse to be caught from the wild all across the UK, threatening natural stocks and risking ecological imbalance. More about the damages of wild wrasse capture for the Scottish salmon farming industry

Farmed or wild caught, these cleaner fish are then all culled at the end of a production cycle (roughly 22months), despite some wrasse species living for over 20 years in the wild. These fish do not enter the food chain, resulting in millions of wasted fish each year across the globe. A report by found that 150,000 cleaner fish die every day on Norwegian salmon farms.

Reliance on wild caught fish for feed

If it wasn’t already enough that the salmon farming industry needlessly kills millions of “cleaner” fish a year, it’s heavy reliance of wild caught fish in salmon feed is even more alarming.

Because of the carnivorous nature of Atlantic salmon, it is estimated that for the Scottish salmon farming industry to achieve its planned annual production increase to 400,000 tonnes of farmed salmon, it will need to increase its use of wild fish from around 460,000 tonnes a year, to 770,000 tonnes a year.

Read more about the unsustainable nature of wild caught fish for feed, and the impact this can have on the communities which value these fish for food

Tides of change

An increasing number of books and news articles across the globe are highlighting the serious issues connected to open-net salmon farming, slowly revealing the true reality. 2022 saw the release of the much-anticipated “Salmon Wars: The Dark Underbelly of Our Favourite Fish. This powerful read from multi-award-winning investigative journalists Douglas Frantz and Catherine Collin exposes the unappetising truth about the global salmon farming industry. Find and more about this book and where to get your copy

As awareness of the harm of salmon farming increases, chefs, food writers and the public are choosing to not eat farmed salmon, instead reaching for more sustainable and environmentally friendly options.

Read more from food writer Joanna Blythman on why she stopped eating Scottish farmed salmon